Platform rocking-chair



2 Sheets Shet 1.

(No Model.)

W. I. BUNKER.

PLATFORM ROCKING UHAIR.

No. 669,446. Patented Oct. 13, 1896.

(No Model.) 2 Sheets-Sheet 2.

w. I. BUNKER; PLATFORM ROCKING CHAIR.

No. 569,446. Patented Oct. 13, 1896.

zflz izadfiw: I Men 4771' I W/zanv [Ban 2192",

UNITED STATES PATENT OFFICE.

\VILLIAM I. BUNKER, OF LA GRANGE, ILLINOIS.

PLATFORM ROCKING-CHAIR.

SPECIFICATION forming part of Letters Patent No. 569,446, dated October 13, 1896.

Application filed be 12, 1893, Serial N01 493,481. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM I. BUNKER, a citizen of the United States, residing at La Grange, Illinois, have invented certain new and useful Improvements in Platform Rocklug-Chairs, of which the followingis a specification.

My invention, while it has relation to platform rocking-chairs, has more specifically to do with the means by which the rocking is effected; and the invention consists, in general terms, in the construction and arrangement of parts, as hereinafter described and claimed.

In the drawings, Figure l is a side elevation of a platform rocking-chair containing my invention; Fig. 2, a plan view of the same with the seat portion of the chair removed; Fig. 3, an elevation of the rocking coil or spring; Fig. 4, a side elevation of a rockingchair provided with a modified form of coil or spring; Fig. 5, a plan view of the same with the seat portion removed.

In making my improved platform rockingchair 1 preferably make a base A and a seat portion B in the usual way, except that neither the base nor the seat portion is provided with a rocking-surface. On the contrary, the upper surface of the base-rails and the lower surface of the chair-frame may be plain horizontal surfaces which would prevent the one from rocking on the other unless other means were provided for securing rocking-surfaces. I interpose between the base and the chair-frame, where both are used, a rocking coil orspring O, which holds them apart so that their surfaces do not contact with each other. The rocking coil or spring may be made in different'ways, and I have illustrated two forms in which it may be constructed in the drawings. In the first three figures I have represented the helical coil or spring as of a diameter practically equal to the diameter of the chair, as will be understood from an inspection of Fig. 2. The helical coil or spring is preferably made up of a continuous strip of material, the lower and upper ends of which are fastened to the chair-base and chair-frame in any suitable manner. Fig. 2 shows holes 0, through which the fastening may be efiected by screws or other convenient means. The strip composing the rocking coil or spring is thin or beveled at its front and rear sides, so as to leave spaces, as at a, between the coils. This thinning or beveling of the coils forms the rocking-surfaces, which enable the seat portion of the chair to rock or oscillate back and forth when the chair is in use. I

The material composing the rocking coil or spring may be made of bent wood or of steel or other suitable material, but I do not desire to limit myself in this respect. As the chair oscillates on the rocking coil or spring the coils composing it will open in front as the chair oscillates backward and in the rear as the chair moves forward. Of course as the coils open in front they will close in the rear, and vice versa, thus operating as stops to limit the extent of the backward or forward movement, which can be regulated by the extent to which the coils are thinned at the front and rear, thus making large or small spaces between them.

In the drawings I have shown the bottom surface of the bottom coil of the rocking coil or spring as flat, so as to adapt it to rest on a plain or flat surface. This will permit the platform to be dispensed with and the rocking coil or spring itself to rest upon the floor. In such case it can, of course, be provided with casters to facilitate the movement of the chair from place to place. In like manner where the chair-frame is made circular, as is frequently the case, it can correspond to the size of the upper coil of the rocking-coil, so that the rocking-coil and the chair-frame will thus virtually merge the-one into the other.

In Figs. 4 and 5 I have shown two rockingcoils, one at each side of the chair. In this arrangement the coils are elliptical instead of circular in form. In other respects, however, they are in construction and operation substantially the same as in the first three figures of the drawings, and what I have said in describing them is also applicable to the modified form shown in Figs. 4 and 5. In both arrangements I have a portion adapted to receive a rocking motion and a portion that is adapted to serve as a combined stationary and rocking support therefor.

While I have shown and described the parts forming my improved platform rockin g-chair with some minuteness of detail, I do not mean to limit myself to such details further than I may call for or specify the same in the claim. I regard the rocking coil or spring as embodying' the essential, or at least the most impor tant, feature of my present inventiomwhether used by itself or in connection With a platform or base, and I desire in my claim to broadly cover such rocking coil or spring. I may also say that I do not mean to confine myself in the use of the rocking coil or spring to chairs technically, but expect to use it in connection with cribs, cradles, and similar articles. For convenience, however, I have used the term chair in the specification and claim to designate all of the various articles to which my rocking coil or spring may be applied.

Hy improvements are intended as being applicable to rocking-chairs only as contradistinguished from tilting chairs in that in mine the rocking-surfaces form a continuous changing fulcrum, While tilting chairs are understood as having one or more points which act as positive fulcrum-points and do not give the easy gradual rocking motion of the rockin g-chair with its constantly and continu ously changing fulcrum.

What I regard as new, and desire to secure by Letters Patent, is

In rocking-chairs, the combination of a portion adapted to be rocked, a rocking coil or spring the coils of which are thinned or beveled on that side of the center of oscillation in which the rocking is to take place, and a base, substantially as described.

, \VILLIAM I. BUNKER.

\Vitnesses:

THOMAS F. SHERIDAN, SAMUEL E. HIBBEN. 

